Liquid level gauge



July 25, 1950 G. SARUCHANOFF LIQUID LEVEL GAUGE Filed June 5, 1938 Jm/en for: I fw? Patented July 25, 1950 UNITED ferri-ce LIQUID 'LEVEL GAUGE VlOvClarns.

'This invention 'relates @to improvements in measuring 'instruments .fior fascertaining the Weig-letgof a liquid stored :in y.containers .such asgasoline tanks.

11n my "fathers U. S.ispecificationr No. 2;033,153 an instrumen-t Aof this `-kind is i-described by means of which the Weight of -i1he-liquidfis ascertained by eineasuring cthe lhydrostatic pressure Voi "the liquid with zthe :aid "of a :U shaped pipe lled With'rmercury, "one :leg of isaid pipe communicating with ithe Lliquid in the tank 'and the Aother with' a 7line 'of r'compressed Bair. zeroeadjusting zdevice :permits yfof 'zadijusting the mercury level Ain feach case 'of measuring.

ln fanimproved modification fof fthfs apparatus described in fmyffGerman Patent INo. 1654,350, the zero-adjusting Yfdevice is "adjusted by means of an felectrcd-e firmly attached 'to the 1tf1-:pipe in combination "with a displacerfthe aero-'adjusting ldevice fleeing yadjusted' -ito *zero-position lby hand, whereas the 'adjustmentfoif the `fuil Pnydrostatic pressure :in regard *to "the zero-position (above :zero `lis .iautomaticaily effected by lmeans of Ithe :stationary electrode.

Now the object o"f the zpresent *invention is 'to adjust automatically also the zero-"adjusting device to Zero-position, so that the apparatus eX cept the manipulation'vgovernedby an opticfand an acoustic `signal'of a svvitch'anda cock lis entirely operated automatically. According Ato the invention, klvfor this fpurpos'e, all valves "for introdu'cing into or withdrawing ffrom the JlU-pipe the liquid to 'be fwe'ighed and 'the 'air 'under pressure are automatically adjusted, for instance, 'by opening 'or'closing the Valv'esby'means o'f a single electric switch. All the valves 'are constructed as is Well-known in the form of electrovalves which are opened or closed'bylan electric'current so that they are closed or opened respectively when the current isinterrup'ted.

The y'automatic Vadustrrren't o"`f the zeroaiijustin'g fdevice vto zero-position on fthe 'onehand of 4the `full hydrostatic 'pressure iintl'ieftank to this zero-*position on the yother hand 'especially affords the essential advantagewffa fgreater eX- actness of measuring, =because -this adjustment is quite independent of =thesight and-manipulations Yof the operator whereby `difieren-t adjustments of the Vsame zeroeposition-unavoidable when adjusting by handalinear as excluded. Furthermore hereby an increased safety in Work ing the measuring device and an extraordinary simplification of its use and manipulation are ootained, as the Whole measuring operation can'be 'carried out, for "instance, by one single f'svvitch,

"2 after the cock, .con-trolling .the inflow of the mercury from the displacer `into the .U-pipe or the-.refiefcinto .thefdisplacen hasibeen-iopenedfand subsequentlyiclosed, preferably Foy -h-and.

.The :measuring device according :to #the rinvention is preferably constructed suchfa Ymanner that the :liquid-controllingvalues fof the U-pi-pe for fcontrolling the ladjxustm'ent of the yZero-ad .i ustment device A'to the zero-level of :the ftank 4and the ocmpressed-air-Valve of`theclfi-splacer fform: an electr-ic circuit t'o he fclosed Vby fthe fswitch, that the vvalve yfor 4vadmitting thefcompressed dair to the ctisplacer aand therelectrode :in thefrightehand leg of the U-pipe V:form sa second 4circuit to be closed byl Arising .mercury, :that ethe valves :for admitting fthe Yt-ank :liquid and "the compressed air under the full "hydrostatic pressurefof the tank form-a third felectric circuit (to-be tclosed 'in :another position) with gthe compressed 'air 4outlet valves :closed `in this fmom'ent, :and t'hat when setting `.the switch into azthifrd 'position .the valve for :admitting *the 'tank liquid fis opened 'and fthe compressed air outlet valve'iis` opened y'and Tis automatically close'd iunder the full hydrostatic pressure 'las :soon `"as fthe 'zero-position fof vthe zero-:adjustingfdeviceis attained, .Af'further feature fof lmy invention vconsists l-therein `that the mercury contained in the displacing device .'i's automatically' displaced A'towards the 1U-'pipe and shut off-for .adjusting "the zero-position whereas :my previous modification the :displacement was'feitected by `a differential :piston .for 'a Y{1i-exible diaphragm `'adjusted .by hand where'bytin 'accuracies in xadFj-us'ting "the 'zero-adjusting device to the standard level TN--YN might be fentaliled.

Furthermore 1in order ito preventth'e mercury from' tpassing for Yanry treason whatever yout 'of the U-'pipe -in'to the compressed air line, 'instead Vof thefc'heck valve provided 'for in the Sdevice :of 'Pati ent TNO. 2033153, according Ito 'itliis invention 'a contact is inserted iinto fthe circuit 'of -the 'electro` Valfvevcon'troliing lthe admission of the ltankliquid to the 1U pipe.. Said contact being securedto'the lett-hand 'leg Vfof the U-pip'e l'opens the 'circuits loT the lelectrovalye when the mercury in the lefthand leg *falls beneath said Ycontact, 'whereby the furtherino'w `of 'the tank vliquid into fthe Uepipe is 'automatically shutoff.

En the fdraviing an example of the measuring 'device according to thenvention is diagrammatically'lllustrated.

`lNear -the bottom o'f "the tank jl 'the 'pipe "2 is arranged which V'is provided'wth a shutting-off lslide (-notshoivnVafnd `a"hand.:'operated control Vfvfalv'ei t0 be able tofcon'trlthe lovv of the itank liquid from the tank into the U-pipe 6 when the slide is in open position. Behind the control valve 3 an electro-valve 4 is provided for the purpose of increasing safety in working the measuring device. This electrovalve is inserted into an electric circuit in such a manner that the opening oi the valve and the flow of the tank liquid from vthe tank into the U-pipe can only take place by adjusting the change-over switch 36, i. e. only while the measuring is done by the operator. Furthermore in the circuit of the electrovalve 4 the contact 32 in the lower left-hand leg of the U-pipe is inserted in such a manner that when the mercury falls below the contact 32 the circuit is interrupted or disconnected, whereby the valve 4 is closed and the passing of mercury into the compressed air line I9 is prevented which could take place by inadvertence of the operator, for instance, by suddenly opening the control valve 3. A socket 8 connects the left hand leg 6 of the U-pipe with the electrovalves I and 4. The outlet 5 of valve 'I represents the Zero-level N-N of the stored liquid which is transferred to the right-hand leg of the U-pipe whence the respective hydrostatic pressures of the tank may be ascertained `by means of the present measuringr device. The outlet 5 also serves for letting off air-bubbles which might have collected in the liquid contained in the left-hand leg of the U- pipe; this outlet is closed and opened by the electrovalve '1. For obtaining greater accuracy of the zero-position to be transferred to the right-hand leg of the U-pipe the left-hand leg may have a somewhat greater diameter. Both legs preferably made of glass communicate with a duct I i3 of the connecting body 9. Said duct I is provided with a cock II for lling the U- pipe with mercury or removing the mercury from it in order to clean both parts. The duct I0 communicates also with the displacing vessel I and may be disconnected therefrom by the cock I2 operated by hand.

The supply from the vessel I5 of the mercury required for adjusting the zero-position in the right-hand leg of the U-pipe is effected according to the invention by means of compressed air flowing from the container 23 through line I8 and the electrically controlled inlet valve I6 and forcing the mercury while cock I2 is open from the displacing vessel into the U-pipe fi until it touches the stationary electrode 3f, whereby as explained hereafter, in the same moment the valve I6 is shut off, the signal-lamp 33 flashes up and the acoustic signal 34 sounds so as to remind the operator to close cock I2 by hand. Subsequently, when another circuit including the electrovalve I1 is interrupted, the compressed air may escapefrom the displacing vessel I5 into the open air through said electrovalve I'I, then open, as will be described hereinafter.

To the socket 8 on the right-hand leg 6 of the U-pipe is connected the compressed air line I9 communicating with the container 20, another branch leading to the exactly measuring gauge 28 communicating at its other end through line 29 and hand-operated cock 30 with the air-space of tank I to subtract at onceany gas-pressure acting upon the liquid when reading off the hydrostatic pressure at the gauge 28. The compressed-air container isy pumped up by the hand pump 22 vand is provided with a simple control-gauge 2l for indicating the requiredpressure` In the `compressed-air line I9 an inlet valve 23 and an outlet valve 24 are provided likewise actuated by electricity, valve 23 being, for instance, opened and valve 24 closed by the current. The object of the valve 24 is to let the compressed air escape from the line I9 only gradually so that the mercury in the right-hand leg of the U-pipe rises only slowly and the valve 24 is shut on precisely at the moment when the rising mercury-level touches the electrode 3|. This circuit, of course, cannot be identical with the circuit by which the valve 24 previously was kept closed while the valve 23 was opened, as now valve 23 must also be closed so as to prevent the compressed air from entering line I9. The outlet valve 24 opens toward a container 21 provided with a throttling device 26 which is intended to deaden and to avoid as far as possible the oscillations of the gradually escaping mass of air, whereas the escape of the compressed air is to be retarded by the throttling in order to obtain a calm and slow rising of the mercury. An electric outlet valve 25 is further attached to the air container 2l which remains closed during the measuring operation, i. e. while the compressed air gradually escapes through valve 24, and is only opened after the measuring has been finished in order to rapidly remove the compressed air out of the line I9.

The signal lamp 33 is connected in such a way that it flashes up at each contact of the meniscus of the mercury with the point ofthe electrode 34, that is at each occurrence of the Zero-position, due to the circuit closed hereby, whereas the lamp is extinguished when` this circuit is interrupted by the falling mercury leaving the electrode. A sound signal 34 is included in the circuit containing the signal lamp 33 and the electrode 3|, if the cock" I2 is in open position. As soon as the rising mercury contacts the electrode 3l, said sound signal 34 is rendered operative and remains in operative condition until the cock I2 is closed and the circuit is interrupted. For this purpose the cock I2 is provided with a contact I3 whichis in engagement with the contact I4 of the circuit of the signal-lamp 33 and the acoustic signal 34 when the cock is opened, and which contact I3 is disengaged from the contact I4 of said circuit when the cock is closed, so as to interrupt said circuit.

The electric current for the dierent circuits is supplied by a storagefbattery 35 A and B, whereas by connecting the switch 36 with the different knobs, for instance, a, b, c, the circuits required for the automatic adjustment of the zero-positions for the zero-level IN--N and the full hydrostatic pressure are connected or disconnected. 'Ihe terminals for connecting all electrovalves 4, l, I6, I1, 23, 24, 25, the signal lamp 33, the switch 36 and all other parts of the measuring device tobe connected with the circuits are denoted by 3l. The electrcvalves 4, I and 23 are closed when not energized and are open when energized while the electrovalves I5, Il, 24 and 25 are closed when under current and are open when not energized. In order to avoid the formation of sparks at the contacts, a corresponding number of` condensers may be inserted into the electric lines. The storage bate tery consists of two separate parts 35A and 35B enclosed in a common box, each part having independent terminals.

The measuring device may be operated as follows:

First connection- The Valve 3 is opened slightly by hand so as to ll the left-hand leg ll lgauge 28 and the gauge again indicates the exact pressure of the liquid in the tank.

The circuit of the valve 4 is further connected to the contact 32 in the left-hand leg of the U- pipe. When the pressure in said left-hand leg surpasses a certain value, for instance when an insufficient quantity of compressed air is supplied to the right-hand leg of the U-pipe, the mercury in said right-hand leg excessively rises and may under certain conditions enter the air line I9.

The safety contact 32 arranged in the left-hand leg of the U-pipe prevents the mercury from an undesired excessive rising in the right-hand leg of the U-pipe. As soon as the mercury in the left-hand leg falls below the conta-ct point 32, the circuit of the valve 4 is interrupted, whereby the valve 4 is closed and the supply of the liquid from the tank l to the U-pipe is stopped.

Of course, the invention is not limited to the modication shown and described in the present speciiication, but includes all other modications in which the zero-adjustment device provided at the U-pipe is automatically adjusted for the zerolevel N--N of the tank as well as for its full hydrostatic pressure which may be effected, for instance, by means of one single switch 36 as shown or, if desired, in another way.

While the liquid conductor in the U-pipe 5 is described as being mercury, it may consist of any other suitable liquid not miscible withthe liquid in the tank i and being a conductor of electricity, such as an aqueous solution of sodium sulfate. In this case alternating current may be used for actuating the valves to avoid the development of gases.

I claim:

l. In an apparatus for ascertaining the hydrostatic pressure of the liquid in a container the combination of a U-shaped pipe having a lirst and a second leg and having a bow connecting said legs, said U-pipe containing a liquid not miscible with the liquid in the container and being a conductor of electricity, the first leg of which pipe communicates with the liquid in the container near the bottom of the latter, a vessel, a source of compressed air, a. rst line connecting said source of compressed air with said vessel, a second line connecting said source of compressed air with the second leg of the U-pipe, said vessel communicating with the bow of the said U- shaped pipe and lled with the same liquid conductor as the latter, a pressure gauge attached to the said second line, electrovalves arranged firstly between the container and said first leg of the U-pipe, secondly between the said vessel and the source of compressed air, and thirdly between the said second line and the source of compressed air, electrically controlled outlet valves on the first leg, on the vessel and on the said second line, a hand-controlled cock between the bow of the U-pipe and the vessel, an electrode in said second leg of the U-pipe, an optic signal to be operated by the contact of the electrode with the liquid conductor, an acoustic signal to be operated by said hand controlled cock and a single switch adapted to selectively connect the said valves with a source of electricity. .i

2. In an apparatus for ascertaining the hydrostatic pressure of the liquidin a container the combination of a U-shaped pipe having a rst and a second leg and having a bowl connecting said legs, said U-pipe containing a liquid not miscible with the liquid in the container and being a conductor of electricity, the first leg of which pipe communicates with the liquid in the container near the bottom of the latter, a vessel, a source of compressed air, a rst line connecting said source of compressed air 'with said vessel, a second line connecting said source of compressed air with the second leg of the U-pipe, said vessel communicating with the bow of the said U-shaped pipe and filled with the same liquid conductor as the latter, a pressure gauge attached to the said second line, electro-valves arranged firstly between the container and said first leg oi the U-pipe, secondly in said rst line between the said vessel and the source of cornpressed air, and thirdly between the said second line and the source of compressed air, electrically controlled outlet valves on the rst leg, on the vessel and on the said 4second line, a handcontrolled cock between the bow of the U-pipe and the vessel, an electrode in the second legcf the U-pipe, an optic signal to be operated by the contact of the electrode with the liquid conductor, an acoustic signal to be operated by said hand-controlled cock and a switch adapted to establish one circuit over the electrovalve opening under current located between the container and the iirst leg of the U-pipe and said valve connecting the liquid in the rst leg of the U- pipe with the open air, a first battery, a second battery, the valve between the source of compressed-air and the vessel being Aopen if not energized, the outlet valve on the vessel being closed under current-whereby the liquid conductor in the second leg of the U-pipe is raised and a circuit is shunted over the liquid conductor, the electrode in the second leg of the U-pipe, the optic signal, the valve in said rst line, said second Ibattery and back to the liquid conductor, another circuit over the rst battery, the valve between the container and said rst leg of the U-pipe, a second outlet valve of the compressed-air line, said iirst outlet valve of the compressed air line, the valve between the compressed-air line and the source of compressed air-whereby the shunt circuit is interrupted and the full hydrostatic pressure in the container is made to act on the liquid conductor in the first leg of the U -pipe and the full air pressure is allowed to act on the liquid conductor in the second leg of the U-pipe, so as to separate the liquid conductor from the electrode in this leg until the circuit is broken by the next actuation of the switch and thereby the valve between the compressed air line and the source of compressed air is closed and the rst outlet valve on the compressed air line is opened and a third circuit over the Erst-named battery, the valve between the container and said first leg of the U-pipe, and the second outlet valve of the compressedair lines-whereby the full hydrostatic pressure is balanced with the pressure in the compressedair line connecting the second leg of the U-pipe with the pressure gauge.

3. In an apparatus for ascertaining the hydrostatic pressure oi a liquid in a tank, the cornbination of: a iJ-pipe having a iirst and a second leg and having a bow connecting said legs, said U-pipe containing an electro-conductive liquid not miscible with the liquid of the tank, the first leg of said U-pipe communicating with said tank near the bottom thereof, a pressure gauge, a rst line connecting said pressure gauge with ihe interior of the second leg of said U-pipe, a vessel, a second line connecting the bow osaid U-pipe with said vessel, a hand-operated cock atrasos arranged-i in. said.' second line', said. cock being .setta'ble inan open: position wherein. said. vessel communicates with the bow of said U-pipe and being settable, in'. av closing position wherein said vessel.' is disconnectedl from: said Uf-pipe, a source .of compressed. air, a. third lineconnecting'. said source. of' compressed air with said vessel, a first electrovalvei in said third line for opening and closing same, a secondi electrovalve: connected with said: Vessel for connecting same with the open air in.- openz position and for closing. same in closing position, an electric. source, automatic electric means responsive;` to| the rising oiv the liquid in said. secondleg of the U-pipe beyond; a predetermined,v level. for connecting. said@ nest electrovalver said. electric source. so as` to bring; same into. closing. position, and a switch ior connecting said second electroualve withsaid electricy source so vas to bring. same.v intoclosing position and for' disconnecting said second electrovalxfe from. said: electric source so asv to bring same into open position.

4. In an: apparatus for ascertaining the hydrostatic: pressure ci aliquid in a tank,. the combination of: a U-pipehaving a ilrst andasecond leg and. having a bow connecting said'` legasaid lil-pipe containing an electroconductine liquid not miscible with the liquid of the tank, the

nrst leg ofsaid Upipe comfrnunicating with said tank near the bottom` thereof, a. pressure gauge, a. iirst line connecting said. pressure gauge with the interior of. the second leg ofv said U-pipe, a vessel, a second line connecting theY bow of; said U-pipe with said vessel, a.-hancloperated cock in said. second line, said cock being settahle `in an, open position wherein said vessel communicates with the bow. of said U-pipe and being settable. inv a. closing position wherein saidv vessel is disconnected from. said U-pipe, a sourcel-of compressed air, a third line connecting said source. ofy compressed air with said` vessel, a

fourth line` connecting said. sourcel oi compressed air with said iirst-line, a iirst electrovalve in said third line for opening and closing same, asecond electrovalve insaid fourth line for opening and: closing same, a iirst. electrically controlled outlet vali/'e connected withv said vessel, a second electrically controlled outlet valve connected with. said rst line, a third; electrically controlled outlet valve connected with said' first leg oi the. lJ.-pipe, an electric source,l automatic electric. means.. responsive to the rising of the liquid` in. said secondV leg oi the Ui-pipe beyond a predetermined. level for connecting said yfirst electrovalvewithasaid electric source so as to energize said electrovalve for closing said third line, said second. electrovalve and said electrically controlled outlet valves being in. electrical connections'with said electric source and. a changeover switch in said electrical connections for selectively energizing and de-energizing said secondA electrovalve and said electrically con; trolledi outlet valves.

5.. I-n anapparatus as claimed in claim. 4, said iirst leg of the U-pipe communicating with said tank through a iifth line, a third electrovalve in said fifth line for opening and closing same, said third electrovalve being in electrical connectionv with said electric source and being open .whena energized, andi automatic. electrical safety, means responsive to the falling of the liquid in the rst leg below a predetermined level for disconnecting said third electrovalve from said electric source so as to de-energize said electrovalve for closing said fth line.

6... 15:1x ani apparatus as claimed lin! claim'. 4,. said automatic electric. means: includingfanr electrode arranged.- in said. second. leg ofthe; U -pipe for contact. with the liquid therein'. when the" liquid risesr beyond a predetermined level,.. a switch connected with. said cock, said switchV being automatically' closed. whenV the Icoclr` .is opened andbeing automatically opened when. the cock is closed, and at. least one. electric signal, said rst'electrovalve; saidA electric, source, said cockcontrolled. switch, the liquid of the U -pipe,A said felectroda. and. said` electric signal constituting a --circuit 1 '7.Y In an; apparatus as claimed .in claim 4 said automatic.' electrimieans' including an electrode .arranged-.1in said secondy leg. of the.` Ll-pipe for Contact. with: thee liquidi therein'. when the liquid ,rises'xheyond a predetermined. level.; a. switch -saidterminals;` a rstcircuit-including said electricnsourca. the first set. of terminals of said change-over switch, said first outlet Valve and .saidv third. outlet valve;A a second circuit includingf saidA electric source said rst electrovalve, said; optical signaL, said electrode, the liquid of the lJ-pipe,I saidf cock-operated switch and said acoustical signaL, said acoustical signal being arranged between said switch. and said electric source; said` optical signal being arranged between saidf rst electrovalve and said electrode;

,a third circuit including said electric source, the

second.-v set` of terminals of said change-over switch, said second electrovalve and said Second outlet'val-ve; and a fourth circuit including said electric source, the third set of terminals of said change-over switch, said second outlet valve, said optical signal. said electrode and the liquid of thel U-pipe. k

8. Ln an apparatus as claimed in claim 4, said rst legof the U-pipe communicating with said tank through a; fifth line, a third electrovalve in said fth line for opening andclosing same, said automatic electric means including a rst electrode arranged in said second leg of. the U-pipe for contact with the liquid therein when the liquid rises beyond a predetermined level; a

second electrode arranged in said rst leg of the U-pipefor disengagement from the liquid therein when the liquid fallsI below'apredetermined level; a switchI connected with said cock; said switch being lautomatically closed when the cock is opened andy being. automatically opened when thecoclrisclosed; an optical signal; an acoustical signal; said rst electrovalve, said first outlet valve-and said second outlet valve being open when` ole-energized and beingA closed when energ-ized, said second electrovalve, said third outlet. valve and said third electrovalve being closed v,when de-energized and: being open when energized; said changer-euer switch including a rst, a second and a third set of terminals and a contacting element cooperating with said terminals; a rst circuit including said electric source, the rst set of terminals of said change-over switch,`

`ing open when energized;

said first outlet valve, said third outlet valve 'and said third electrovalve; a second circuit including said electric sourcesaid first electrovalve, said optical signal, said first electrode, -the liquid of the U-pipe, said cock-operated switch and said acoustical signal, said acoustical signal being arranged between said switch and said electric source, said optical signal being arranged between said first electrovalve and said first electrode; a third circuit including said electric source, the second set of terminals of said change-over switch, said second electrovalve, said second outlet valve and said third electrovalve; a fourth circuit including said electric source, the third set of terminals of said changeover switch, said second `outlet valve, said optical signal, said first electrode and the liquid of the U-pipe, said third electrovalve being connected in parallel to said fourth circuit; and a fth circuit including said electric source, said third electrovalve, said second electrode and the liquid of the U-pipe.

9. In an apparatus as claimed in claim 4, said first leg of the U-pipe communicating with said tank through a fifth line,.- a third electrovalve in said fifth line for opening and closing same, said automatic electric means including a first elecv trode arranged in said second leg of the U-pipe for contact with the liquid therein when the liquid rises beyond a predetermined level; a second electrode arranged in said first leg of the U-pipe for disengagement from the liquid therein when the liquid falls below a predetermined level; a switch connected with said cock; said switch being automatically closed when the cock is opened and being automatically opened when the cock is closed; an optical signal; an acoustical signal; said rst electrovalve, said first outlet valve and said second valve being open when deenergized and being closed Awhen energized; said second electrovalve, said third outlet Valve and said third electrovalve being closed when de-energized and besaid change-over switch including a iirst, a second and a third set of terminals and a contacting element cooperating with said terminals; a rst circuit including said electric source, the first setvof terminals of said change-over switch, said first outlet valve, said third outlet Valve, said third electrovalve, said second electrode and the liquid of signal, said first' electrode, the liquid of the U-pipe, said cock-operated switch and said acoustical signal, said acoustical signal being arranged between said switch and said electric source, said optical signal being arranged between said first electrovalve and said electrode; a third circuit including said electric source, the second set of termin-als of said change-over switch, said second electrovalve, said second outlet valve, said third electrovalve, said second electrode and the liquid of the U-pipe; a fourth circuit including said electric source, the third set of terminals of said change-over switch, said second outlet valve, said optical signal, said rstelectrode and the liquid of the U-pipe; and a fifth circuit comprising said third electrovalve and said second electrode, said fifth circuit being connected in parallel to said second outlet valve and said first electrode of said fourthv circuit,

10. In an apparatus as claimed in claim 4, said first leg of the U-pipe communicating with said tank through a fifth line, a third electrovalve in said fth line for opening and closing same, a container, a throttling outlet on said container, a fourth electrically controlled outlet valve on said container, said second outlet Valve communicating with said container, said automatic electric means including a rst electrode arranged in said second leg of the U-pipe for contact with the liquid therein when the liquid rises beyond a predetermined level; a second electrode arranged in said rst leg of the U-pipe for disengagement from the liquid therein when the liquid falls beyond a predetermined level; a switch connected with said cock; said switch being automatically closed when the cock is opened and being automatically opened when the cock is closed; an optical signal; and acoustical signal; said rst electrovalve, said rst outlet valve, said second outlet valve and said fourth outlet valve being open when de-energized and being closed when energized; said second electrovalve, said third outlet valve and said third electrovalve being closed when de-energized and being open when energized; said change-over switch including a rst, a second and a third set of terminals and a contacting element cooperating with said terminals; a first circuit including said electric source, the first set of terminals of said changeover switch, said rst outlet valve, said third outlet valve, said third electrovalve, said second electrode and the liquid of the U-pipe; a second circuit including said electric source, said iirst electrovalve, said optical signal, said rst electrode, the liquid of the U-pipe, said cock-operated switch and said acoustical signal, said acoustical signal being arranged between said switch and said electric source, said optical signal being arranged between said rst electrovalve and said electrode; a third circuit including said electric source, the second set of terminals of said changeover switch, said second electrovalve, said second outlet valve, said fourth outlet valve, said third electrovalve, said second electrode and the liquid of the U-pipe; a fourth circuit including said electric source, the third set of terminals of said change-over switch, said second outlet valve, said optical signal, said first electrode and the liquid of the U pipe; and a fifth circuit comprising said fourth outlet valve, said third electrovalve and said second electrode, said fifth circuit being connected in parallel to said second outlet valve and said first electrode of said fourth circuit.

GEORG SARUCHANOFF;

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,805,849 Sartakoff May 19, 1931 1,811,801 Murphy June 23, 1931 1,819,655 Mohr Aug. 18, 1931 2,033,153 Saruchanoif Mar. 10, 1936 FOREIGN PATENTS Number Country Date 37,706 Great Britain; Nov. 4, 1935 

